Technical Field
The present disclosure relates an exhaust treating apparatus and more particularly to a recirculated-suspension pre-calciner system.
Description of the Related Art
In 2006, the energy industry, i.e. energy converting industry released 164086000 tons of CO2 which was 61.86% of the total release of fuel combustion in Taiwan if departments do not share CO2 used for electricity power. But, if departments share CO2 used for electricity power, the energy industry, i.e. energy transferring, released 18509000 tons of CO2 which was 6.98% of the total release of fuel combustion in Taiwan. According to the data described above, CO2 from the energy industry electricity generating for the departments is 54.88% of total release of fuel combustion, which almost exceeded half of the total release of CO2 in Taiwan. Therefore, if the release of CO2 from power plants can be effectively captured, the release of CO2 can be reduced significantly.
The cement industry is a major contributor to the release of CO2, but air combustion and equipment's sealing are not good enough, such that even a calciner is performed to generate CO2, the release of flue gas only has a CO2 concentration of 25-30%. A new CO2 capture technology is required for increasing the CO2 concentration to gain a beneficial result of CO2 reuse and sequestration. In addition, the cement industry is one of six consuming energy industry, which the process uses air combustion and usually the process does not prevent heat dissipation. Therefore, heat loss is too much and fuel utilization efficiency is low. One method to increase efficiency is to recover waste heat to generate electricity power, but it has a high cost and requires a large space. Furthermore, the conventional technology cannot get business opportunity of lightweight calcium carbonate.